A tunnel boring machine from the East Side Access project emerges in Sunnyside, Queens (file / credit: MTA)

NEW YORK (CBSNewYork/AP) – A fleet of massive tunneling machines that has spent 4 1/2 years digging 13 miles of new train tubes deep beneath New York City finally fell silent this week after the last of the monsters finished its mission.

The Metropolitan Transportation Authority announced Wednesday that the machine had completed its work, thus ending a remarkable run in which seven such machines dug 16 new tunnels for the agency’s trains in a little under five years.

MTA chairman Joseph Lhota said in a statement that the feat “reminds us that New Yorkers remain capable of great achievements.”

WCBS 880’s Rich Lamb reported that while Lhota called this a milestone, commuters should take note that the LIRR service isn’t expected at Grand Central until 2019.

In addition to linking LIRR trains to Grand Central, the authority is also building a new subway line beneath 2nd Avenue on Manhattan’s East Side, and extending the No. 7 subway line on the West Side.

To dig the tunnels, engineers operated the boring machines around the clock. Each used an array of steel cutting discs, powered by 6 million pounds of thrust, to reduce Manhattan’s granite to muck.

With all of their trailing gear, some of the contraptions were nearly 360 feet long.

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